Got my 393 on the road this week. For those contemplating a stroker, by all means do it. It was well worth the trouble and I am more than happy witht he results.

 

tell us what your running it in, efi setup, parts used etc...

 

Yeah! Also did you put it on a dyno? If so, what HP & Torque. By all means tell us the recipe.

 

This was a close to stock rebuild for my work truck. 3,85 stroker, stock 351 rods, 303 dished pistons, 8.9-1 compression, Comp RV type cam, late 351 69cc heads, mild bowl and chamber work, iron 4bbl intake and 525cfm street demon, duraspark dist and MSD, headers and 2.5 Flowmasters. Nothing trick or fancy, but pulls tons better than the stock 351. RPM rarely sees 4000. Pulls a 10000lbs with a C6 and 3.55 gear. Not much HP but a lot of torque from idle to about 4800 where the cam goes away. Motor cam out just the way I expected. Lots of torque on 87. I am happy. I can see where one of these with some RPM goodies would make a killer street motor.

 

Yeah did you put it on the dynometer. I bet it put out atleast 400hp!! thats cool is in a work truck so that you can say you have a sleeper. Wouldnt you want to run that Vp gas to be on the safe side? it smells cool too! are you running a 9 inch rear end?

 

400 HP? No way, maybe 250HP with 400 lb/ft of torque. Couldn't make that much without some good heads and intake with a cam to go along with it. VP gas at over $5 a gallon doesn't sound like fun. I'm running a Dana full floating rear due to the weight. A 9" would be unsuitable in my application.

 

Yeah, definitely no horsepower there.

That motor is breathing through a straw.

Those cubes need huge amounts of air...with the right components 500hp/500tq are easily attainable.

 

Breathing through a straw? Wouldn't you run an air filter? If this farm truck sucks enough dust and straw, you would have to rebuild it all over again. 500hp should move 10,000 lbs. Building a 393 for my camaro now. Thanks.

 

um....


"breathing through a straw" is a mediphor for saying it's choked and doesn't get a lot of airflow.


For 393 cubic inches...it needs a lot more air than a 351 or lesser cubes. He is essentially starving it of air by using those parts....which is giving him pitiful horsepower numbers and lower torque numbers....


But it seems to be good enough for him and that's all that matters.

 

Chevy guys?

 

393x4800rpm (WarW say's) = 1,886,400 divided by 3456 = 545 (cfm) x .9 (street use)
= 491 cfm needed to feed that motor (525cfm being used) . I talked to War wagon via Email and he said the heads/intake he had ported were done by a professional. So this motor combo is a good set up overall for brute torque. I wonder how it drives? Sorry folks for the dry comments earlier. it just gets the snow ball roll'n... I don't own a Camaro

 

The heads and intake were worked over by a very savy racer known for making big power in Pontiacs. He must have done a good job, cuz this thing kicks *** in the low rpm range. This motor tuned out exactly the way I told him I wanted..........Smooth idle and stump pulling torque. He told me I would be wasting my money on aluminum heads. Save those for the racers. We ar going to put the truck on the chassis dyno next week just for fun. I will keep you posted.

 

Your formula is meaningless even though you think it isn't. 490 cfm is not nearly enough to adequately feed a 393 motor.

Like I said, his motor has parts on it that don't flow worth of squat compared to what's out there. That combination doesn't make high horsepower at all...it makes decent torque from the stroke of the engine.

He'd make 10 times more power if he put bigger parts on it...but he didn't and he got what he wanted and didn't have to spend much to get it...more power to him.

If we were using a much larger budget....we'd use much larger components...stuff that flows 300 cfm PER cylinder...and make more torque everywhere in the RPM band...have a flatter tq band...and make about 100+ more ft-lbs of torque.


Now that is the kind of torque that'll break your neck when snapping that throttle...but you've gotta have the horsepower as a byproduct and the only way you get that is with RPM and torque.

This guy's motor is a pretty good match in components, but they're small.

408bronco is ravamping his 408 because of some mismatched components. This time around he is going with much much larger components...

He should probably make about 500-550 hp and about that in torque.

That's just peak numbers though...if you looked at other information as well you'd find that even though the other motor is an RV style motor with a lot of torque down low....i bet his motor would still make more tq down low...as well as over 100ft-lbs more up top.

 

War Wagon... You should have put a 1050cfm Dominator so you can make that 550+hp mark. What is the proper cfm required? The formula for street carb cfm, that I got out of 'Auto Math' on page 43 was the wrong formula, According to mustangt221. I should have looked up a formula to decrease fuel economy, and to make high rpm hp for a stroker motor using stock parts. Using h beam rods, Single Plenum manifold (gotta have that 1" spacer) and aluminum heads would be cool but the torque curve is bumbed up from off idle to a 8" 4000 rpm stall coverter, drag racing work truck?

"Using hp as a byproduct", that sounds like the hp and torque curve are side by side
when we all know (I hope) that as the torque curve poops out the hp curve moves up later in the rpm band, crossing always at 5252rpm. What gets a car moving from a green light? why do we downshift to pass a slow truck on the freeway? Why can we cruse down the freeway doing 70mph @ 1700 rpm (65 speed limit)?

I hope this helps.
War Wagon... Did you see the clown suit at Woodroad #5?

 

Sure you can use a formula to determine the size of the carb required...I didnt' say it was the wrong forumla...but it's the wrong formula to use in determining what heads/intake/etc to put on the engine.

It's used for figuring out what carb to use and it's only ballpark.

Apparently what I'm saying isn't making sense to you.

408bronco is doing what I talked about and I will be doing something similar in the future when my budget grows.

These motors have rediculous protential and can make crazy power. Even if you make it have a tq peak at 4000+ and rev to 6000-6500...it'll still make the same or higher tq (depending on the setup) down low than what he built. It'll still have great low end tq just like we all want in a truck...but it'll have 550hp to knock your block off if you decide to step on it and rev it out.